1. Field of the Invention
This invention relates to an apparatus and method for recording optical disks, both those suitable for recording and those suitable upon reproduction, for example, reversible-type optical disks capable of being repetitively recorded and reproduced, or write-once type disks.
2. Description of Prior Art
When recording such disks, pits (or marks) are formed on a repetitively recordable and reproducible optical disk, or a write-once read-many type optical disk, and the amount of laser light to be irradiated on the optical disk, the amount of recording light, has to be maintained to be a proper value. This is because the recorded pits are required to have a uniform shape and a high density in order to reduce error upon reproduction and improve the recording density.
According to the prior art, in order to set the amount of recording light at a proper value, a "try-to-write" region is prepared on a track within a predetermined user's recordable region of the optical disk, and the user confirms the proper amount of recording light within this try-to-write region.
When information is recorded at the confirmed proper amount of recording light, the recording density of a recorded region near the try-to-write region can be improved since a relatively small error occurs upon reproduction.
However, when a video signal is recorded over the whole disk, i.e. the innermost to outermost periphery of the user's recordable region of the optical disk, the amount of recording light, even if it is set to be a proper value within the try-to-write region as mentioned above, diverges from the proper amount at other tracks away from that region because the linear velocity of the recording medium (which depends on the radius of the track) is considerably different from that within the try-to-write region. This limits the high-density recordability.
Increasing the amount of testing, however tends to occupy more time and thus be inefficient. Also, although it has been proposed to provide a test area in every sector and test at every radius (e.g. in computers WD2000 and WD3000) this reduces the amount of available storage area and so is unsuitable for video disks where more data is generally stored than on a computer disk.